German Pat. No. 26 46 395 shows a cover for servicing holes in automotive service stations, comprising a band of parallel support members pivotably connected with one another and supported at their ends on horizontal guide rails arranged at the upper longitudinal edges of the hole, the band of support members being longitudinally displaceable; a driving motor for displacing the band of support members.
The support members of this known structure are necessarily longer than the width of the servicing hole. Therefore the width of the hole must be broadened at one end of the hole for the vertical run of the support members. This can be accomplished easily if new holes are built. In contrast to that the known cover arrangement cannot be used for existing holes having parallel side surfaces and therefore being of constant width over the whole length of the hole, without a remarkable rebuilding of the hole.